I love sandals, and when I'm not barefoot I very rarely wear anything else. Even my slippers are really mule sandals (or 'slides') of one kind or another. Slidey flip-floppy sandals are fine for indoors. But when I step out, I need ankle straps, to keep me in my shoes. And a sandal looks very different depending on the strap. I don't know what the shoe industry calls each of these styles, but here are the names I use:

The choker strap --> the least common of the three. Looks like a choker necklace or a clergyman's collar.

The bridle strap <-- which is what I wear most often. Comfortable because it doesn't rub. Resembles a horse's bridle.

The halo strap --> aesthetically, my favourite. It's just super sexy and elegant.. It's like the choker but is suspended above the shoe like a halo, I think. All shoes are by Clark's, the British shoe manufacturer.